This invention relates to pop-up irrigation sprinklers, and more particularly, to a new and improved sprinkler retaining cover and sealing assembly for ensuring that a pop-up sprinkler mechanism can not become dislodged from within its protective case, and for effectively sealing the internal sprinkler mechanism against the entry of water, mud, sand, silt, dirt and the like when the sprinkler is not in operation.
Typically, pop-up sprinklers are used in situations when it is desirable to embed the sprinkler in the ground so that it does not project appreciably above ground level when not in use. In such pop-up sprinkler applications, the sprinkler mechanism is typically housed within a cylindrical upright case having an open upper end through which the pop-up portion of the sprinkler mechanism supporting a nozzle assembly can extend during irrigation periods. When not in use, the sprinkler mechanism is retracted within the case, and a cover, typically attached to the pop-up nozzle assembly, seats over the open upper end of the case to close the opening. Such arrangements have long been used with both rotary and non-rotary pop-up sprinklers, such as, for example, is disclosed in U.S. Pat. Nos. 4,625,914 issued Dec. 2, 1986 to Sexton et al.; U.S. Pat. No. 4,892,252 issued Jan. 9, 1990 to Bruninger; U.S. Pat. No. 4,919,337 issued Apr. 24, 1990 to Van Leewen et al. (each relating to rotary pop-up sprinklers); and U.S. Pat. No. 4,913,352 issued Apr. 3, 1990 to Witty et al. (relating to a non-rotary pop-up sprinkler).
In some such pop-up sprinklers, the pop-up sprinkler mechanism is secured within the sprinkler case by a releasable lock ring disposed below the cover and which seats within a groove formed around the inside of the case. Typically, the lock ring projects radially inwardly over a retaining ring such that to remove the sprinkler mechanism from the case, the lock ring must first be compressed and removed from its seated position within the groove, thereby to free the retaining ring for disassembly through the case opening. Exemplary of such pop-up sprinklers are those currently marketed by Hunter Industries under its model number G400, and by the Toro Company under its model numbers 660, 690 and 734.
One problem which has been encountered with the use of pop-up sprinklers employing lock rings to secure the sprinkler mechanism within the case is that of effectively sealing the lock ring and its mounting groove so that water, mud, sand, silt, dirt or other material can not seep inside the case during periods of non-use and clog the groove to prevent lock ring removal. Typically, over time as the surrounding turf or plants grow, the sprinkler becomes recessed relative to the surrounding soil, thereby allowing pools of water and mud to accumulate over the top of the sprinkler, such as may occur after an irrigation cycle has been completed, or as a result of rain or water run-off. Unless an effective seal is made between the sprinkler cover and the upper end of the case, such water, mud, dirt or other material may seep into the case resulting in the lock ring and groove becoming clogged or fouled, and, in areas when freezing conditions may be encountered, damage to the sprinkler mechanism within the case may occur as a result of expansion as the water turns to ice.
Another problem that has been encountered is that the lock ring may become unseated from its mounting groove as a result of vibrations caused by the repeated extensions and retractions of the pop-up sprinkler mechanism during use. Should the lock ring become unseated, the pop-up sprinkler mechanism will become dislodged from its mounting in the case, and hence, the sprinkler will cease to operate.
The present invention overcomes these problems by providing a sprinkler retaining cover and sealing assembly which insures that water, mud, sand, silt, dirt and other material can not enter the sprinkler case during periods of inoperation, and which prevents the lock ring securing the internal sprinkler mechanism within the case from inadvertently becoming loose or unseated, thereby ensuring that the sprinkler mechanism does not become dislodged during use.